The size of the brush fire at Keauhou Ranch has doubled overnight, scorching 3,205 acres within Hawai‘i Volcanoes National Park.

The fire broke out Sunday and continues to burn in several areas on the slopes of Mauna Loa. Jessica Ferracane, spokeswoman for Hawai‘i Volcanoes National Park, said the fire is approaching the Kipuka Ki Special Ecological Area, 2 miles north of Highway 11.

Fire crews from the National Park Service and the Hawaii Island Incident Management team are continuing to battle the fire, which is 5 percent contained.

Kipuka Ki, described as one of the rarest old-growth native forests of its kind in the world, contains tall ohia, koa and manele trees that are vital to the survival of threatened and endangered plants and animals.